The invention relates generally to handling of large containers such as drums, and, more particularly, to a support device to facilitate emptying of residue from such containers.
Large steel and plastic drums are used throughout the world for storage, shipment and dispensing of various fuels, lubricants, solvents, and other industrial and agricultural chemicals. In the United States, 55 gallon steel drums have been commonly used for many years for such purposes Pumps are typically employed to remove the contents. In the past, in removing liquids from such drums in industrial applications, it was common to leave a residue of about two liters in the containers, due primarily to limitations of the pumping equipment typically employed for dispensing the liquid contents The drums would then often be discarded with little regard for the ultimate disposition of the residue.
Recently, government regulations and public awareness of the potential environmental impact of various substances have led to interest in tighter control over disposal of residual amounts of substances left in such drums after the bulk of the substance has been dispensed. Economic considerations are also served by minimizing waste of residual amounts of material which remain in the drum after use of the bulk of the material.
Pumps in use today are generally capable of removing a greater percentage of the drum contents than the older pumps mentioned above, but still typically leave a residue of some 200 to 300 milliliters of fluid in the drum. Removing the residues is a time consuming and expensive problem for the drum reconditioning industry. If fluid residues are not removed promptly after usage of the bulk of the drum contents, the problem may be compounded by liquids which thicken or dry over time due to evaporation of volatile components or other factors, requiring the use of chemical solvents, burning, or other difficult and expensive steps to clean the drum.
Common configurations of drum lids (heads) include the "standard" lid wherein the lid is generally convex; and configurations wherein the lid is generally concave, such that its lowest point is at its center. In both, a spout (flanged opening) is typically located adjacent the periphery of the lid. In some drum lids, two spouts are provided, 180.degree. apart from one another, adjacent the periphery of the lid. The drum lid is typically joined to the upper edge of the cylindrical drum sidewall by an annular projecting chime. The bottom wall is similarly joined to the lower edge of the sidewall.
Polyethylene drums differ slightly from steel drums with respect to the configurations of the peripheral areas of the lids. Rather than a chime as described above with respect to the steel drums, the typical polyethylene drum has a handling ring with a relatively deep groove defined by the interior of the handling ring and the exterior of the lid surface directly inward of the handling ring. The exterior surface of the lid has a generally horizontal central portion and a frustoconical portion extending outward therefrom to the base of the handling ring.
It has been found that removal of much of the residual liquid from a drum can be accomplished by inverting the drum and maintaining it at an inclination of 5.degree. to 10.degree., with the spout, or one of the spouts, at the lowest point. One specifically designed commercially available racking system, known as the Valcline racking system, provides means to support a row of several drums side-by-side in inverted position at the desired inclination, elevated a few inches from a supporting surface. The drums must be lifted onto the rack, and left on the rack for a period dependent on the viscosity of the liquid being drained from the drum. A locating pin facilitates placement of the spout over a receptacle for collection of residual contents.
This racking system has been found to provide a relatively convenient means for facilitating drainage of residual liquids. However, there is a need for means to enable emptying of residue from large drums and the like in a safe, efficient, and economical manner in commercial and industrial applications where known commercial rack systems may be less than ideal due to space constraints, cost, or other considerations.